In order to use Canada Post, you'll need to ensure you are using a valid Canadian address as your store location. You'll also need to ensure your Craft Commerce default currency is set to CAD.
The below service are available with Canada Post for domestic and international customer destination addresses.
Add the following code to your configuration file under the providers array, as per the below. Note that to disable certain services, simply omit them from the services array.
'providers' => [
'canadaPost' => [
'name' => 'Canada Post',
'settings' => [
'customerNumber' => 'xxxxxxxxxxxxx',
'username' => 'xxxxxxxxxxxxxxxxxxxxx',
'password' => 'xxxxxxxxxxxxxxxxxxxxx',
],
'services' => [
'DOM_EP' => 'Expedited Parcel',
'DOM_RP' => 'Regular Parcel',
'DOM_PC' => 'Priority',
'INT_PW_ENV' => 'Priority Worldwide envelope INTL',
'USA_PW_ENV' => 'Priority Worldwide envelope USA',
],
],
]